1. Field of the Invention
This invention relates to a cooling plate structure of a cooling apparatus and a transmitter with the cooling apparatus.
2. Description of the Related Art
The cooling plate structure which is used in a cooling apparatus for cooling a plurality of heat generating elements has been well known. The conventional cooling plate structure includes a cooling plate and at least one refrigerant circulating conduit extending in the cooling plate. The cooling plate has an excellent thermal conductivity and an outer surface to which the plurality of heat generating elements are connected thermally. The at least one refrigerant circulating conduit has an excellent thermal conductivity, includes a refrigerant introducing port and a refrigerant discharging port both of which are exposed on the outer surface of the cooling plate, and extends from the refrigerant introducing port to the refrigerant discharging port in the cooling plate.
For example, it is well known that the transmitter, particularly a transmitter for broadcasting, generates a large amount of heat during its operation. If the temperature of the transmitter is raised, various electric or electronic elements which constitute an electric circuit of the transmitter cannot perform a predetermined function. Thus, a conventional transmitter is provided with a cooling apparatus for cooling these various electric or electronic elements which constitute the electric circuit.
The conventional transmitter usually uses a cooling apparatus which employs the aforementioned cooling plate structure. And, electric or electronic elements each of which generates relatively large amount of heat (hereinafter referred to as heat generating elements), for example power amplifiers, in the various electric or electronic elements constituting the electric circuit of the conventional transmitter, are connected thermally to the cooling plate of the cooling plate structure. In this specification, “Thermally connected” includes any connecting style which allows heat transmission.
The cooling plate is formed of a material having an excellent thermal conductivity, such as copper, aluminum, and alloy thereof. As the refrigerant, for example, water mixed with antifreeze solution is used. The refrigerant is supplied from a radiator to the refrigerant introducing port of the refrigerant circulating conduit of the cooling plate structure, and absorbs heat transmitted to the cooling plate from the heat generating elements while the refrigerant is circulated in the refrigerant circulating conduit in the cooling plate. Then, the refrigerant is returned to the radiator from the refrigerant discharging port of the refrigerant circulating conduit, and, after heat is radiated from the refrigerant by the radiator, the refrigerant is supplied from the radiator to the refrigerant introducing port of the refrigerant circulating conduit of the cooling plate structure.
In the technical field of the transmitter in recent years, amount of heat generated from the heat generating elements of the transmitter increases with improvement of the performance of the transmitter, so that it has been strongly demanded to improve the cooling performance of the cooling plate structure of the cooling apparatus used in the transmitter.
Japanese Patent Application KOKAI Publication No. 2005-197454 discloses a cooling plate structure of a cooling apparatus for a transmitter, which has an improved cooling performance as compared with that of the conventional cooling apparatus. In this cooling plate structure, the refrigerant introducing port and refrigerant discharging port of one refrigerant circulating conduit are arranged side by side on the cooling plate, further a flow-in part of the refrigerant circulating conduit, which extends from the refrigerant introducing port to an intermediate position between the refrigerant introducing port and the refrigerant discharging port, meanders and a flow-out part of the refrigerant circulating conduit, which extends from the intermediate position to the refrigerant discharging port, also meanders adjacently to the flow-in part. Specifically, the refrigerant circulating conduit is partitioned into the flow-in part and the flow-out part by a common partition wall except at the intermediate position and meanders from the refrigerant introducing port to the refrigerant discharging port in the cooling plate.
A plurality of heat generating elements are disposed on the cooling plate to correspond to plural positions along the adjacent flow-in and flow-out parts of the single refrigerant circulating conduit. Each of the plural heat generating elements has an opposed surface which opposes each of the corresponding positions, and each heat generating element is disposed at each corresponding position such that halves of the opposed surface correspond to the flow-in part and the flow-out part of the refrigerant circulating conduit, respectively.
With such a conventional cooling plate structure, the plural heat generating elements disposed at the plural positions along the adjacent flow-in and flow-out parts of the one refrigerant circulating conduit on the cooling plate can be cooled equally.
However, in the conventional cooling plate structure, it is a troublesome work to partition the refrigerant circulating conduit into the flow-in part and the flow-out part by the common partition wall except at the intermediate position. Further, the area (that is, heat exchanging area) of the outer surface of the refrigerant circulating conduit making in contact with the cooling plate while the refrigerant circulating conduit extends from the refrigerant introducing port to the refrigerant discharging port in the cooling plate is small as compared with a case where the flow-in part and flow-out part of the refrigerant circulating conduit are not disposed adjacently to each other with any common partition wall but independent from each other. That is, there is a large difference in cooling performance between a narrow band-like area along the adjacent flow-in and flow-out parts of the single refrigerant circulating conduit and the other area on the cooling plate. As a result, the cooling performance of the entire cooling plate having such a conventional cooling plate structure is smaller than that of the cooling plate structure in which the flow-in part and flow-out part of the refrigerant circulating conduit are not disposed adjacently to each other with any common partition wall but independent from each other.
Further, the kinds of work for thermally connecting the plural heat generating elements directly to the plural positions along the adjacent flow-in and flow-out parts of the single refrigerant circulating conduit on the cooling plate are limited, because the work must be done so as not to damage the adjacent flow-in part and flow-out part of the refrigerant circulating conduit at each corresponding portion. For example, after each heat generating element is connected thermally and directly onto a heat generating element supporting member which is made of excellent heat conductive material and which is configured to cross over the adjacent flow-in part and flow-out part of the refrigerant circulating conduit at each corresponding position on the cooling plate, both end parts of the heat generating element supporting member with the heat generating element are fixed to both outer sides of the adjacent flow-in part and flow-out part of the refrigerant circulating conduit at each corresponding position on the cooling plate with fixing members made of excellent heat conductive material, for example, fixing screws.
Such a heat generating element supporting member not only makes the conventional cooling plate structure having the above-described configuration being complicated but also makes an assembling work thereof being troublesome, thereby reducing the efficiency of heat transmission from the heat generating elements to the corresponding positions on the cooling plate.